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United States Environmental Protection Agency
EPA Region 1 - Valley Depth in Meters
Raster of the Depth in meters of EPA-delimited Valleys in Region 1. Valleys (areas that are lower than their neighbors) were extracted from a Digital Elevation Model (USGS, 30m) by finding the local average elevation, subtracting the actual elevation from the average, and selecting areas where the actual elevation was below the average. The landscape was sampled at seven scales (circles of 1, 2, 4, 7, 11, 16, and 22 km radius) to take into account the diversity of valley shapes and sizes. Areas selected in at least four scales were designated as valleys.
Studies (e.g., J.G. Su et al., Air Qual Atmos Health (2013) 6:85-94) have shown a correlation between areas with higher population and lower topography in New York and New England with elevated air pollution, especially from wood smoke, during winter air inversions. To take advantage of these study results, we developed a regional digital model (i.e., map) that defines valleys and highlights populated valleys in a consistent manner throughout New England. This model uses publicly available topography and population data and can be replicated in other US regions or states. This tool is intended for use by managers to help with planning air-quality monitoring, outreach, and mitigation. For example, the tool may be used to identify valleys at risk for wood-smoke pollution, to review locations of existing air-quality monitors and to identify potential new monitoring sites, to prioritize areas for woodstove changeouts or other woodsmoke mitigation or outreach efforts, or for planning routes for mobile air-quality monitoring.
Time Period of Content
West Bounding Longitude:
East Bounding Longitude:
North Bounding Latitude:
South Bounding Latitude:
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Environment and Conservation
US Environmental Protection Agency
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Metadata Reference Information
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FGDC Content Standard for Digital Geospatial Metadata
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